Justin Bieber Gets Ripped: His Diet and Workout Routine

Justin Bieber has been working out and flaunted his rippling six-pack abs at New York Fashion Week’s Fashion Rocks event last week.

Bieber took the stage alongside model Lara Stone to introduce singer Rita Ora and then decided to strip down after being met with boos from the audience. Bieber then took off his clothes and stood on stage in nothing but his Calvin Klein underwear in a bid to subdue the crowd. “I don’t feel comfortable unless I’m in my Calvins,” he said. “Is that better? Is that cool?”

The stunt worked, as the audience did quiet down. Bieber later revealed on Instagram that the strip tease had been totally unplanned. “Just stripped on national television,” he wrote. “Hahahaha, it wasn’t planned lmao.”

Bieber has chronicled his physical transformation during the past year with regular Instagram photo updates that show him morphing from a skinny teen into a buff young man. Bieber, 20, regularly posts photos of himself pumping iron at the gym. Bieber has filled out a lot from years past, when the lanky Canadian pop star weighed in at a mere 108 pounds.

Bieber said he has been lifting weights seriously for the past two years in a bid to bulk up. “I’ve been working out in the gym, getting bigger, trying to get sexy for the ladies,” he said on Twitter.

Bieber previously trained with “The Biggest Loser” star Dolvett Quince, author of The 3-1-2-1- Diet. Quince stopped working with Bieber when he joined “The Biggest Loser” in 2011.

Bieber’s current trainer, Patrick Nilsson, said he typically trains 40 minutes each day, five days a week, mostly lifting weights and focusing on building up his chest and shoulders.

“I want him to look like Marky Mark,” Nilsson told ABC News. “I feel like this is what he needs to get where he wants to be. He’s definitely leaner and a lot stronger.”

Bieber doesn’t follow a special diet, and his trainer said the focus is on making sure the singer consumes enough calories, since he sometimes forgets to eat due to his busy schedule.

“It’s more about making sure he eats,” said Nilsson. “He’s the only client I allow to have McDonald’s whenever he wants. But he also likes chicken breast, whitefish, salmon, turkey, steak, rice, mashed and regular potatoes and weird greens like cauliflower.”